1. Field of the Invention
This invention relates to aerators for ponds, lakes and the like. In one of its aspects, the invention relates to an aerator for turbulently aerating water and circulating the aerated water to the bottom portion of a lake.
2. State of the Prior Art
Lack of oxygen is one of the greatest of fish killers, both in summer and winter. During the summer, water will usually absorb oxygen during cool nights. However, several hot, humid nights can reduce the oxygen in water to a danger point. for this reason, aerators have been developed to return oxygen to bodies of water.
One such aerator is disclosed in U.S. Pat. No. 3,086,715 to Paul J. Mineau et al, issued Apr. 23, 1963. This aerator is principally designed for small trout ponds. The Mineau et al aerator pump draws water up through a tube and sprays the water into a plurality of vertically spaced sheets of water to entrain the air in the water.
Larger lakes are also subject to effects of oxygen loss, including the loss of oxygen to eutrophication. Aerators typically take water from a top portion of the lake and spray the water along the top surface thereof in a manner similar to the Mineau et al aerator pump. For example, see Henegar U.S. Pat. No. 4,030,859 (issued June 21, 1977) and Earhart et al U.S. Pat. 3,836,130 (issued Sept. 17, 1974). Henegar provides a telescoping tube from which water can be drawn from a bottom portion of the lake and aerated at the top of the lake. Earhart et al provide an electrical heater in a difuser plate for inhibiting formation of ice on the aerator. However, in large bodies of water, lack of oxygen near the bottom of the lake can be acute.
The patent to Hirshon U.S. Pat. No. 3,794,303 (issued Feb. 26, 1974) discloses a floatation ring aerator with an intake column and a discharge column. A head on one column is provided by the introduction of air into the other column which serves both to raise and to aerate the water therein. In one embodiment, mechanical means are provided to circulate the water through an aeration means and deposit the thus aerated water near the bottom of the lake.
Heretofore, the efficient technique of spraying the water through the air to entrain air therein has not been utilized to provide aerated water near the bottom of a lake.